[Problem] Scripts Placed Under Cron Folders Don't Work
If you place some scripts under /etc/cron.hourly or /etc/cron.daily and other Cron folders. You may notice that they do not work, or an error message like this appears:
run-parts: failed to exec /etc/cron.daily/script: Exec format error run-parts: /etc/cron.daily/script exited with return code 1
This means you didn't specify the shell to use in the beginning of the script.
Just insert #!/bin/bash or #!/bin/sh at the beginning of your scripts. Like:
#!/bin/bash echo "Some text here" apt update ...